1. Field of the Invention
This invention is directed to new 1-[(dialkylamino)methyl]-6-phenyl-4H-s-triazolo[4,3-a][1,4]-benzodiazepine N.sup.1 -oxides.
The novel compound and the processes of the production therefor can be illustratively represented as follows: ##STR2## wherein X is chlorine or bromine; wherein R' and R" are alkyl of 1 to 3 carbon atoms, inclusive; wherein R.sub.1 is hydrogen, fluoro, chloro, bromo, nitro, trifluoromethyl or alkylthio in which the alkyl moiety is of 1 to 3 carbon atoms, inclusive; and wherein R.sub.2 is phenyl, o-chlorophenyl, o-fluorophenyl, or 2,6-difluorophenyl.
The invention also embraces the pharmacologically acceptable addition salts of the compounds II.
The new compounds are remarkable as they show a different spectrum of activity from the known parent compounds without the N-oxide group, namely: ##STR3## wherein R', R", R.sub.1 and R.sub.2 have the definitions above listed, which is generically claimed and disclosed in British Pat. No. 1,331,015, sealed Jan. 16, 1974, and specifically disclosed in U.S. Pat. No. 3,842,090, issued Oct. 15, 1974. While these compounds III above have sedative, tranquilizing and antidepressant activity, the N.sup.1 -oxide compounds II thereof only have sedative-tranquilizing activity, i.e., a split activity.
The compound 1-[(dimethylamino)ethyl]-8-chloro-6-phenyl-4H-s-[4,3-a][1,4]benzodiazepine (U.S. Pat. Nos. 4,012,413 and 3,759,943) has a particularly strong antidepressant activity with sedative activity lesser than commercial tranquilizers and thus differs from both compounds of formulae II and III. Finally, U.S. Pat. No. 3,681,343, issued Aug. 1, 1972, discloses an N-oxide generically prepared by direct oxygenation with a peracid. U.S. Pat. No. 3,681,343 was reissued as U.S. Pat. No. Re. 28505 Aug. 5, 1975, without the generic or any specific claims to N.sup.5 -oxide compounds.